Exploiting the basis of proline recognition by SH3 and WW domains: design of N-substituted inhibitors.Nguyen, J.T., Turck, C.W., Cohen, F.E., Zuckermann, R.N., Lim, W.A.
(1998) Science 282: 2088-2092
- PubMed: 9851931
- DOI: https://doi.org/10.1126/science.282.5396.2088
- Primary Citation of Related Structures:
1B07, 2SEM, 3SEM
- PubMed Abstract:
Src homology 3 (SH3) and WW protein interaction domains bind specific proline-rich sequences. However, instead of recognizing critical prolines on the basis of side chain shape or rigidity, these domains broadly accepted amide N-substituted residues. Proline is apparently specifically selected in vivo, despite low complementarity, because it is the only endogenous N-substituted amino acid. This discriminatory mechanism explains how these domains achieve specific but low-affinity recognition, a property that is necessary for transient signaling interactions. The mechanism can be exploited: screening a series of ligands in which key prolines were replaced by nonnatural N-substituted residues yielded a ligand that selectively bound the Grb2 SH3 domain with 100 times greater affinity.
Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94143, USA.